feat: 全站 PageShell 设计系统与专业 UI 统一

- 新增 PageShell/PageTabs/ContentPanel/PageLoading/PageEmpty 页面骨架
- index.css 设计令牌文档化，布局令牌与纯色主按钮（去除渐变粉彩）
- 全站路由页接入 PageShell，云账单三 Tab 为标杆
- 主题体系：跟随系统 + 主流/开发者分组，新增 Dracula/Tokyo Night，One Dark 暖灰差异化
- 登录页/侧栏/顶栏去渐变光球，企业克制风
- 修复 AIAlertAnalyzer JSX 与构建依赖导入问题

frontend/src/components/deploy/credential-manager/CredDetailDialog.tsx

@@ -88,10 +88,10 @@ export function CredDetailDialog({ open, onClose, credId }: CredDetailDialogProp
               </div>
               <div><span className="text-[var(--dg-text-muted)]">状态：</span>
                 {detailRecord?.is_active
-                  ? <Badge className="bg-green-500/20 text-green-400 text-xs ml-1"><CheckCircle2 className="h-3 w-3 mr-0.5" />启用</Badge>
-                  : <Badge className="bg-red-500/20 text-red-400 text-xs ml-1"><XCircle className="h-3 w-3 mr-0.5" />禁用</Badge>}
+                  ? <Badge className="bg-green-500/20 dg-text-green text-xs ml-1"><CheckCircle2 className="h-3 w-3 mr-0.5" />启用</Badge>
+                  : <Badge className="bg-red-500/20 dg-text-red text-xs ml-1"><XCircle className="h-3 w-3 mr-0.5" />禁用</Badge>}
                 {detailRecord?.expires_at && new Date(detailRecord.expires_at as string) < new Date() && (
-                  <Badge className="bg-yellow-500/20 text-yellow-400 text-xs ml-1"><AlertTriangle className="h-3 w-3 mr-0.5" />已过期</Badge>
+                  <Badge className="bg-yellow-500/20 dg-text-yellow text-xs ml-1"><AlertTriangle className="h-3 w-3 mr-0.5" />已过期</Badge>
                 )}
               </div>
               <div className="col-span-2 cursor-pointer" onClick={() => copyValue((detailRecord?.env_prefix as string) || '')}>
@@ -118,7 +118,7 @@ export function CredDetailDialog({ open, onClose, credId }: CredDetailDialogProp
                 <Key className="h-4 w-4 text-yellow-500" />密钥数据
               </div>
               <div className="p-3 rounded-md bg-yellow-500/5 border border-yellow-500/20 mb-3">
-                <p className="text-xs text-yellow-400/80">以下内容包含敏感信息，请妥善保管，不要泄露给他人。</p>
+                <p className="text-xs dg-text-yellow/80">以下内容包含敏感信息，请妥善保管，不要泄露给他人。</p>
               </div>
 
               {st === 'ssh' && <>